Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.
Department of Laboratory Medicine, Seoul National University Hospital, Seoul, Republic of Korea.
BMC Genomics. 2020 Apr 23;21(1):322. doi: 10.1186/s12864-020-6738-2.
Nontuberculous mycobacterium (NTM) species are ubiquitous microorganisms. NTM pulmonary disease (NTM-PD) is thought to be caused not by human-to-human transmission but by independent environmental acquisition. However, recent studies using next-generation sequencing (NGS) have reported trans-continental spread of Mycobacterium abscessus among patients with cystic fibrosis.
We investigated NTM genomes through NGS to examine transmission patterns in three pairs of co-habiting patients with NTM-PD who were suspected of patient-to-patient transmission. Three pairs of patients with NTM-PD co-habiting for at least 15 years were enrolled: a mother and a daughter with M. avium-PD, a couple with M. intracellulare-PD, and a second couple, one of whom was infected with M. intracellulare and the other of whom was infected with M. abscessus. Whole genome sequencing was performed using patients' NTM isolates as well as environmental specimens. Genetic distances were estimated based on single nucleotide polymorphisms (SNPs). By comparison with the genetic distances among 78 publicly available NTM genomes, NTM isolates derived from the two pairs of patients infected with the same NTM species were not closely related to each other. In phylogenetic analysis, the NTM isolates from patients with M. avium-PD clustered with isolates from different environmental sources.
In conclusion, considering the genetic distances between NTM strains, the likelihood of patient-to-patient transmission in pairs of co-habiting NTM-PD patients without overt immune deficiency is minimal.
非结核分枝杆菌（NTM）是无处不在的微生物。非结核分枝杆菌肺病（NTM-PD）被认为不是由人与人之间传播引起的，而是由独立的环境获得引起的。然而，最近使用下一代测序（NGS）的研究报告了囊性纤维化患者中脓肿分枝杆菌的跨大陆传播。
我们通过 NGS 研究了 NTM 基因组，以检查三对同居的 NTM-PD 患者中可能存在的患者间传播模式，这些患者被怀疑存在患者间传播。共纳入三对同居至少 15 年的 NTM-PD 患者：一对母女患有鸟分枝杆菌-PD，一对夫妇患有细胞内分枝杆菌-PD，以及第二对夫妇，其中一人感染细胞内分枝杆菌，另一人感染脓肿分枝杆菌。对患者的 NTM 分离株以及环境标本进行了全基因组测序。基于单核苷酸多态性（SNP）估计遗传距离。通过与 78 个公开可用的 NTM 基因组中的遗传距离比较，来自两对感染相同 NTM 物种的患者的 NTM 分离株彼此之间没有密切相关。在系统发育分析中，患有鸟分枝杆菌-PD 的患者的 NTM 分离株与来自不同环境来源的分离株聚类。
综上所述，考虑到 NTM 菌株之间的遗传距离，同居的 NTM-PD 患者之间无明显免疫缺陷的患者间传播的可能性很小。
